The present invention relates to building construction, and more particularly to plumbing fixtures used to mount water pipe to studs or joists.
Copper water pipe should not be supported over long distances by extending through holes drilled in studs. Such holes are time consuming to drill and weaken the strength of the stud. Also, water hammer in the pipe can cause the pipe to move in the studs since the holes are typically larger than the outside diameter of the pipe.
A large number of pipe hanging clamps have been developed in the past for supporting thin walled copper water pipe in building constructions. These clamps need to accommodate thermal expansion of the copper pipe. The clamps should not be made of dissimilar metal since galvanic action can cause corrosion. Copper pipe straps are relatively expensive and must normally be nailed to studs.
The following is a list of U.S. patents showing various clamps and hangers in this field:
U.S. Pat. No. 2,216,886--Titled: Holder--Langelier
U.S. Pat. No. 2,992,800--Titled: Pipe Hanger--Madson
U.S. Pat. No. 3,503,580--Titled: Universal Conduit Support Bracket --Levy
U.S. Pat. No. 3,684,223--Titled: Pipe Clamp--Logsdon
U.S. Pat. No. 4,369,945--Titled: Cable Clamps--Mantoan et al.
U.S. Pat. No. 4,379,537--Titled: Cable Hanger--Perrault et al.
U.S. Pat. No. 4,714,218--Titled: Hanger for Pipe Clamp--Hungerford, Jr.
More recently it has been common to surround the pipe with clamps hung on straps nailed between studs. Strap material of this type is widely used and is sold under the trademark HYCO. It has holes punched in the center at regular intervals.
Of the foregoing patented devices, the pipe clamp of U.S. Pat. No. 3,684,223 of Logsdon has been widely used by plumbers. However, it must either be nailed to a stud or secured with screws or bolts to a HYCO strap, which adds time and cost to the plumbing installation.
The CINCH CLAMP trademark plastic pipe hanging clamp recently introduced by CAL PAC WEST has a central peg and two other pegs on either side of the central peg. See U.S. Pat. No. 5,024,405 of McGuire granted Jun. 18, 1991. This device can be rotated into engagement with corresponding holes in a HYCO strap. The principal drawback of this device is that the holes in the HYCO strap are not precision drilled and the pegs are not precisely located on the clamp due to tolerance variations in the injection molding. Therefore it is sometimes difficult, if not impossible, to align the pegs with a pair of holes in the HYCO strap. Also, removal of this device from the HYCO strap once it has been snapped into place is very difficult. This makes it hard to re-mount the clamp if the plumber misjudges the initial location for the pipe mounting.